Duffadash: Also, please not that unlike the retail version, the steam version of Arkham Asylum has Securom with a 4 machine activation limit.
lowyhong: Doesn't the retail version have it too? I thought I read in various places that it also does.
The Retail version uses it ONLY for a disc-check, where as the steam version is somewhat more invasive:
"The Steam version uses SecuROM to instate a 4-activations-per-month policy. It also watchdogs every system resource the game loads, if anything is found that it thinks is out of place, the game crashes. Most disturbingly, these crashes aren't displayed as being generated by SecuROM, they're displayed as general protection faults, making legit customers think that the game is buggy when it's the draconian DRM causing their problems.
The DVD version of the game, on the other hand, uses SecuROM for a simple DVD check, and that is all."
http://forums.eidosgames.com/showthread.php?t=97663